Fgf10 mutant newts regenerate normal hindlimbs despite severe developmental defects.

In amniote limbs, Fibroblast Growth Factor 10 (FGF10) is essential for limb development, but whether this function is broadly conserved in tetrapods and/or involved in adult limb regeneration remains unknown. To tackle this question, we established Fgf10 mutant lines in the newt Pleurodeles waltl which has amazing regenerative ability. While Fgf10 mutant forelimbs develop normally, the hindlimbs fail to develop and downregulate FGF target genes. Despite these developmental defects, Fgf10 mutants were able to regenerate normal hindlimbs rather than recapitulating the embryonic phenotype. Together, our results demonstrate an important role for FGF10 in hindlimb formation, but little or no function in regeneration, suggesting that different mechanisms operate during limb regeneration versus development.

Levels of major and trace metals in the scalp hair of Crohn's disease patients: correlations among transition metals.

Concentrations of 16 metals in the scalp hair of male Crohn's disease (CD) patients (n = 28) were compared to those of male control subjects (n = 25). The majority of patients (n = 20) took an anti-inflammatory agent (mesalazine), and several patients underwent colectomy. A low concentration of serum ferritin was observed in approximately 50% of CD patients due to Fe-deficiency anemia. The concentrations of Fe, Cr, and Co in the hair of CD patients were significantly higher than those of control subjects, and particularly high concentrations were found in CD patients with low serum ferritin. Significant correlations were found among the concentrations of Fe, Cr, and Co in the hair of CD patients, but not in control subjects. In agreement with previous reports, a significant negative correlation was found between ferritin and transferrin concentrations in serum, although the available data in this study was limited (n = 8). Transferrin not only binds to Fe3+ but also to Cr3+ and Co3+, and the amount of transferrin is increased in Fe-deficiency anemia. Thus, the majority of the Fe3+, Cr3+, and Co3+ in the serum of CD patients is likely to bind to transferrin, which may be associated with the higher concentrations of those metals, as well as the significant correlations among those metals in the scalp hair of CD patients. In addition, colectomy may alter the intestinal absorption rate of some metals, while mesalazine may increase the concentrations of Mn and some metals in the scalp hair by chelate formation.

Stable isotope ratios of carbon, nitrogen and selenium concentration in the scalp hair of Crohn's disease patients who ingested the elemental diet Elental®.

RATIONALE: Elental® is an elemental diet widely used as a nutritional supplement for Crohn's disease (CD) patients in Japan. Elental® contains amino acids as nitrogen sources and does not contain selenium (Se), and the δ13 C and δ15 N values of Elental® are markedly higher and lower, respectively, than those of a normal diet. METHODS: We compared the δ13 C and δ15 N values and Se concentration in the scalp hair of CD patients with those of control subjects who ate a regular diet, and estimated the amount of Elental® ingested as a supplement. The δ13 C and δ15 N values and the Se concentrations were quantified using isotope ratio mass spectrometry (IRMS) and inductively coupled plasma mass spectrometry (ICP-MS), respectively. RESULTS: An increase in Elental® ingestion increased the δ13 C value in the hair of CD patients (p <0.05), while it reduced the δ15 N value (p <0.05) and tended to reduce the Se concentration in female patients. CONCLUSIONS: The amount of Elental® ingested could be estimated by the δ13 C and δ15 N values in the hair of CD patients. Furthermore, the Se deficiency in female patients may be predicted from the δ13 C and δ15 N values.

Kanechlor 500-mediated changes in serum and hepatic thyroxine levels primarily occur in a transthyretin-unrelated manner.

The effects of Kanechlor-500 (KC500) on the levels of serum total thyroxine (T4 ) and hepatic T4 in wild-type C57BL/6 (WT) and its transthyretin (TTR)-deficient (TTR-null) mice were comparatively examined. Four days after a single intraperitoneal injection with KC500 (100 mg/kg body weight), serum total T4 levels were significantly decreased in both WT and TTR-null mice. The KC500 pretreatment also promoted serum [125 I]T4 clearance in both strains of mice administrated with [125 I]T4 , and the promotion of serum [125 I]T4 clearance in WT mice occurred without inhibition of the [125 I]T4 -TTR complex formation. Furthermore, the KC500 pretreatment led to significant increases in liver weight, steady-state distribution volume of [125 I]T4 , hepatic accumulation level of [125 I]T4 , and concentration ratio of the liver to serum in both strains of mice. The present findings indicate that the KC500-mediated decrease in serum T4 level occurs in a TTR-unrelated manner and further suggest that KC500-promoted T4 accumulation in the liver occurs through the development of liver hypertrophy and the promotion of T4 transportation from serum to liver.

Fucoxanthin administration delays occurrence of tumors in xenograft mice by colonospheres, with an anti-tumor predictor of glycine.

Fucoxanthin and its major metabolite, fucoxanthinol, have potent anti-cancer properties in carcinogenic model mice and against cancer cells. Evidence has accumulated regarding the diagnostic potential of biological metabolites as invasive and non-invasive obtainable approaches. We recently demonstrated that glycine was an effective predictor of the suppression of sphere formation and epithelial mesenchymal transition by fucoxanthinol in human colorectal cancer stem-like spheroids (colonospheres) under normoxia and hypoxia. In the present study, we investigated the suppressive effect of fucoxanthin on tumorigenesis derived from colonospheres in xenograft mice, and the alteration on the metabolite profiles of mouse tumors by fucoxanthin was evaluated. Fucoxanthin administration at 2.5 mg/kg body weight (p.o.) for 4 weeks significantly inhibited the incidence of tumors by inoculation of colonospheres suspension in BALB/c nu/nu mice compared with control mice, but not tumor sizes. In addition, fucoxanthin down-regulated tumor Cyclin D1 expression by 0.7-fold of that observed in the tumors of the control mice. Moreover, the tumor glycine level in the xenograft mice was decreased by fucoxanthin administration to 0.5-fold. These results imply the possibility of tumor metabolites as a prediction marker of tumorigenicity derived from colorectal cancer stem cells in mice.

Essential and Non-essential Elements in Scalp Hair of Diabetics: Correlations with Glycated Hemoglobin (HbA1c).

Essential elements (Ca, Mg, Zn, Cu, Fe, Cr, Mn and V) and non-essential elements (As, Cd, Hg and Pb) were measured in scalp hair samples of 45 diabetic subjects and 59 control subjects in Japan using inductively coupled plasma mass spectrometry. All diabetic subjects took insulin and/or antidiabetic agents, with glycated hemoglobin (HbA1c) ranging between 6.2 and 14.4%. The levels of Zn, Cu and Cr in the diabetic subjects (HbA1c>7) were significantly lower than those in the control subjects (p<0.05), and these concentrations decreased significantly with increases in HbA1c (p<0.01). The levels of Fe and Mg in the diabetic subjects were insignificantly lower, and the concentration of Fe decreased significantly with increases in HbA1c (p<0.05) and the concentration of Mn tended to decrease (p<0.10). In contrast, the concentration of As tended to increase with increases in HbA1c (p<0.10). The concentrations of other elements, such as Ca, Mn, V, Pb, Cd and Hg, in the diabetic subjects were similar to those of control subjects, and did not correlate with HbA1c. The average of estimated glomerular filtration rate (eGFR) in the diabetic subjects was 77.7±29.7 mL/min/1.73 m2 with large variation (12.7-148 mL/min/1.73 m2), and previous study reported the increase of urinary excretion of Zn, Cr, Mn and Mg in diabetic subjects. The decreases of Zn, Cu, Cr, Fe and Mg concentrations in hair may reflect increased urinary excretion of these elements due to diabetic nephropathy.

In vivo tracking of histone H3 lysine 9 acetylation in Xenopus laevis during tail regeneration.

Xenopus laevis tadpoles can completely regenerate their appendages, such as tail and limbs, and therefore provide a unique model to decipher the molecular mechanisms of organ regeneration in vertebrates. Epigenetic modifications are likely to be involved in this remarkable regeneration capacity, but they remain largely unknown. To examine the involvement of histone modification during organ regeneration, we generated transgenic X. laevis ubiquitously expressing a fluorescent modification-specific intracellular antibody (Mintbody) that is able to track histone H3 lysine 9 acetylation (H3K9ac) in vivo through nuclear enhanced green fluorescent protein (EGFP) fluorescence. In embryos ubiquitously expressing H3K9ac-Mintbody, robust fluorescence was observed in the nuclei of somites. Interestingly, H3K9ac-Mintbody signals predominantly accumulated in nuclei of regenerating notochord at 24 h postamputation following activation of reactive oxygen species (ROS). Moreover, apocynin (APO), an inhibitor of ROS production, attenuated H3K9ac-Mintbody signals in regenerating notochord. Our results suggest that ROS production is involved in acetylation of H3K9 in regenerating notochord at the onset of tail regeneration. We also show this transgenic Xenopus to be a useful tool to investigate epigenetic modification, not only in organogenesis but also in organ regeneration.

Correlations between mercury concentration, and stable isotope ratios of carbon and nitrogen of amino acids in scalp hair from whale meat eaters and heavy fish eaters.

RATIONALE: As mercury (Hg) accumulation in marine animals generally increases with increased trophic level (δ15 N values) through the food web, predators accumulate higher levels of Hg. The main source of human Hg intake is the consumption of fish and other marine animals, and Hg concentration in scalp hair is the preferred marker for evaluating consumption of marine animals. Difference in δ15 N values between trophic and source amino acids of human consumers could enable us to estimate the trophic level of the consumer without knowing the bulk δ15 N value of their prey. METHODS: We measured the δ15 N values of 15 amino acids in scalp hair from heavy fish eaters and whale meat eaters using isotope ratio monitoring gas chromatography/mass spectrometry (irm-GC/MS), and investigated the correlations between Hg concentrations in the hair and the δ15 N values of the individual constituent amino acids. RESULTS: The δ15 N values for all trophic amino acids (Ala, Val, Leu, Ile, Pro, Asx and Glx) increased with increases in Hg concentration (p < 0.01), with the highest correlation being with Glx (R2  = 0.725). In contrast, the δ15 N value for Thr decreased with increases in Hg concentration (R2  = 0.663, p < 0.01). The difference in δ15 N values between Glx and Thr was positively correlated with Hg concentration, showing the highest correlation coefficient (R2  = 0.773, p < 0.01) among the various combinations for amino acids. CONCLUSIONS: The difference in δ15 N values between Glx and Thr appears to be the best proxy for the estimation of Hg concentration in scalp hair. Copyright © 2017 John Wiley & Sons, Ltd.

Accumulation properties of inorganic mercury and organic mercury in the red-crowned crane Grus japonensis in east Hokkaido, Japan.

The red-crowned (Japanese) crane Grus japonensis is native to east Hokkaido, Japan, in contrast to the East Asia mainland. Previously, we reported that red-crowned cranes in Hokkaido were highly contaminated with mercury in the 1990s and that the contamination rapidly decreased to a moderate level in the 2000s. In the present study, we determined levels of organic mercury (O-Hg) in the liver and kidney of cranes in east Hokkaido in comparison with levels of total mercury (T-Hg). T-Hg levels in the kidneys were higher than those in the livers in adults but not in subadults and juveniles; however, the reverse was the case for O-Hg even for adults. The ratio of O-Hg to T-Hg in both the liver and kidney decreased as T-Hg increased in the three developmental stages. While the ratios of O-Hg to T-Hg in the liver and kidney of adults were significantly lower than those of juveniles, the ratios were similar for adults and juveniles in a lower range of T-Hg. The ratio of selenium (Se) to T-Hg decreased as T-Hg increased in both the liver and kidney, irrespective of stages. Mercury burdens in feathers were about 59% and 67% of the total body burdens for juveniles and adults, respectively. Furthermore, ratios of carbon and nitrogen stable isotopes to T-Hg varied greatly, with no relation to mercury level in the liver. The results suggest slow accumulation of inorganic mercury in the kidney of red-crowned cranes in east Hokkaido, Japan.

[Management of patients with ischemic heart disease in lung cancer resection].

We reviewed the medical records of 1,047 consecutive patients with lung cancer who underwent surgery between April 2005 and March 2014. Among them 49 patients(4.7%)had concomitant ischemic heart disease. Coronary angiography showed coronary artery stenosis in 41 patients, of whom 14 patients received bare metal stents and 9 patients received drug-eluting stents. Three patients underwent plain old balloon angioplasty. Coronary artery bypass graft were performed in 5 patients. Eight patients with coronary spastic angina were also included in the present study. Aspirin administration was continued in 9 patients and heparinization was performed in 14 patients during the perioperative period. Postoperative major adverse cardiac events within 30-days occurred in 3 patients(6.1%)resulting in a single fatality(2.0%). No major cardiac events, including stent thrombosis, developed in patient who received coronary stent. Perioperative aspirin administration and heparinization were not significantly associated with intraoperative bleeding during the operation.

[Metabolism of 2,2',3,4,4',5,5'-Heptachlorobiphenyl (CB180) by Animal Liver Microsomes].

The in vitro metabolism of 2,2',3,4,4', 5,5'-heptachlorobiphenyl (CB180) was examined using liver microsomes of rats, guinea pigs and hamsters. Of liver microsomes from untreated animals, rats and guinea pigs produced one metabolite (M-1) with the activity of 1.2 and 18.1 pmol/hr/mg protein, respectively, but hamsters did not at all. Pretreatment of phenobarbital (PB) resulted in about 32-fold increase in rats, 4-fold increase in guinea pigs and an appearance of M-1 in hamsters (15 pmol/hr/mg protein). In addition, another metabolite (M-2) was formed only by liver microsomes of PB-treated guinea pigs. In contrast, pretreatment of 3-methylcholanthrene showed no metabolite in three animals. By comparison of the GC-MS data of the metabolites with synthesized authentic samples, M-1 and M-2 was determined to be 3'-hydroxy (OH)-CB180 and 4'-OH-2,2',3,4,5,5'-hexachlorobiphenyl (CB141), respectively. These results suggest that 3'-OH-CB180 is a major metabolite and is formed by PB-inducible cytochrome P450 (CYP2B enzymes) in animals and also guinea pigs possess much higher activity to metabolize CB180 than rats and hamsters.

Growth and differentiation of a long bone in limb development, repair and regeneration.

Repair from traumatic bone fracture is a complex process that includes mechanisms of bone development and bone homeostasis. Thus, elucidation of the cellular/molecular basis of bone formation in skeletal development would provide valuable information on fracture repair and would lead to successful skeletal regeneration after limb amputation, which never occurs in mammals. Elucidation of the basis of epimorphic limb regeneration in amphibians would also provide insights into skeletal regeneration in mammals, since the epimorphic regeneration enables an amputated limb to re-develop the three-dimensional structure of bones. In the processes of bone development, repair and regeneration, growth of the bone is achieved through several events including not only cell proliferation but also aggregation of mesenchymal cells, enlargement of cells, deposition and accumulation of extracellular matrix, and bone remodeling.

Uptake of aristolochic acid I into Caco-2 cells by monocarboxylic acid transporters.

The uptake mechanism of aristolochic acid I (AAI) was investigated using Caco-2 cells cultured on dishes and permeable membranes. The uptake of AAI from the apical membrane of Caco-2 cells cultured on a dish was rapid, and a decrease in the pH of the incubation medium significantly increased uptake. Incubation at low temperature (4°C) and treatment with sodium azide (a metabolic inhibitor) or carbonylcyanide p-trifluoromethoxyphenylhydrazone (a protonophore) significantly inhibited the AAI uptake. Coincubation with L-lactic acid or benzoic acid, typical substrates for the proton-linked monocarboxylic acid transporters (MCTs), significantly decreased the AAI uptake, as did coincubation with α-cyano-4-hydroxycinnamate (an inhibitor of MCTs). Dixon plotting revealed the competitive inhibition of benzoic acid on the AAI uptake. To confirm the AAI uptake via MCTs, the apical-to-basolateral transport of AAI was investigated using the Caco-2 cells cultured on the permeable membranes. The transport of AAI at pH 6.0 was markedly higher than that at pH 7.4, and was significantly decreased by coincubation with benzoic acid. These results suggest that the uptake of AAI from the apical membrane of Caco-2 cells is mediated mainly by MCTs along with benzoic acid.

3,3',4,4'-Tetrachlorobiphenyl-mediated decrease of serum thyroxine level in C57BL/6 and DBA/2 mice occurs mainly through enhanced accumulation of thyroxine in the liver.

A single intraperitoneal injection (50 mg/kg) of 3,3',4,4'-tetrachlorobiphenyl (CB77), a 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-type polychlorinated biphenyl, led to significant decreases in the levels of serum total thyroxine (T4) and free T4 without increase in the level of serum thyroid-stimulating hormone at 7 d later in both TCDD-sensitive C57BL/6 and TCDD-resistant DBA/2 mice. When [(125)I]T4 was injected into the mice 7 d after treatment with CB77, the levels of biliary [(125)I]T4 and [(125)I]T4-glucuronide increased 90 to 120 min post injection in C57BL/6 mice, but not in DBA/2 mice, compared with levels in the corresponding control mice. In contrast, in both strains of mice, the CB77-pretreatment led to similar changes in the levels of the [(125)I]T4 bound to the serum transthyretin, albumin, and thyroxine-binding globulin. Consequently, treatment with CB77 promoted the clearance of [(125)I]T4 from the serum and further raised the steady-state volumes of distribution of [(125)I]T4, the concentration ratio (Kp value) of the liver to the serum, and the distribution of [(125)I]T4 in the liver in both strains of mice. The present findings indicate that in mice, the CB77-mediated decrease in the serum T4 level occurs through enhanced accumulation of hepatic T4 rather than through increased activity of hepatic thyroxine-uridine 5'-diphosphate-glucuronosyltransferase(s).

Expression of developing neural transcription factors in lung carcinoid tumors.

In lung tumors, the association between carcinoids and high-grade neuroendocrine tumors (HGNETs) is controversial. To understand the phenotypic similarities/differences between lung carcinoids and HGNETs, we comparatively investigated the expression of three kinds of developing neural transcription factors (DNTFs: BRN2, TTF1 and ASCL1) and multiple endocrine neoplasia type 1 (MEN1) as well as RB1 and P53 using 18 carcinoids and 16 HGNETs. The DNTFs were expressed in 10 of the 18 carcinoids and in all the HGNETs, while normal neuroendocrine cells, which are considered the major cell origin of lung carcinoids and small cell carcinomas, did not express DNTFs. Both the DNTF(-) and DNTF(+) carcinoids contained typical and atypical carcinoids. All the DNTF(-) carcinoids examined were formed in the bronchial wall. All the MEN1(-) carcinoids examined were classified into the DNTF(-) carcinoids, while all the HGNETs expressed MEN1. This finding suggests that DNTF(-) MEN1(-) carcinoids are unlikely to be precursors of HGNETs. Although the status of RB1 and P53 between carcinoids and HGNETs were apparently different, the DNTF(+) carcinoids of two male patients and one female patient revealed morphologies resembling HGNET cells and relatively high Ki67 indices. Further investigation of DNTF expression in carcinoids might provide important clues to understand the association between carcinoids and HGNETs.

Steric hindrance of 2,6-disubstituted benzoic acid derivatives on the uptake via monocarboxylic acid transporters from the apical membranes of Caco-2 cells.

Benzoic acid is a typical substrate for monocarboxylic acid transporters (MCTs), and easily taken up from the apical membranes of Caco-2 cells by MCTs. However, some benzoic acid derivatives were sparingly taken up by Caco-2 cells. To elucidate the mechanism of lower uptake of the derivatives, we investigated the effect of substitution of benzene ring on the uptake by MCTs using Caco-2 cells. Among the benzoic acid derivatives tested, the uptake of 2,6-disubstituted benzoic acids was markedly lower than that of other benzoic acids. Co-incubation of the 2,6-disubstituted derivatives with benzoic acid did not decrease the uptake of benzoic acid, while co-incubation with other derivatives significantly decreased the uptake of benzoic acid. Kinetic analyses elucidated that the uptake of 2,6-dichlorobenzoic acid and 2,3,6-trichlorobenzoic acid did not involve the carrier-mediated process. The 2,6-disubstitution of benzoic acid may prevent the access of carboxylic acid group to MCTs expressed on the apical membranes of Caco-2 cells.

Comparison of carbon, nitrogen, and oxygen stable isotope ratios and mercury concentrations in muscle tissues of five beaked whale species and sperm whales stranded in Hokkaido, Japan.

We studied δ13C, δ15N and δ18O values, and total mercury (THg) concentrations in muscle samples from deep-sea predators - five beaked whale species and sperm whales - stranded along the coast of Hokkaido, in the north of Japan in 2010 and 2019. The δ13C, δ15N and δ18O values, THg concentrations, and body length (BL) of Stejneger's beaked whales were similar to those of Hubbs' beaked whales, which belong to the same genus. In contrast, δ13C values, THg concentrations, and BL of Sato's beaked whales were markedly different from those of Baird's beaked whales, which belong to the same genus. Stejneger's and Hubbs' beaked whales living around Hokkaido may compete in their ecological niches, whereas Sato's and Baird's beaked whales may segregate their ecological niches. Although Cuvier's beaked whales and sperm whales belong to different genera and their BLs were significantly different, their δ13C and δ15N values were similar, probably because they can dive and stay in deeper waters than other beaked whale species. The δ13C values in combined samples from all whales increased with increasing BL, probably owing to the larger whale species' dietary preference for squid. The δ13C values in combined samples from all whales were positively correlated with THg concentrations, whereas the δ15N values in the combined samples were negatively correlated. The δ18O values in combined samples from most whales tended to be positively correlated with THg concentrations. These correlations may be explained by a higher THg load from deep-sea feeding than from pelagic feeding and by a feeding shift towards lower trophic levels.

Neural lineage-specific homeoprotein BRN2 is directly involved in TTF1 expression in small-cell lung cancer.

Thyroid transcription factor 1 (TTF1) plays crucial roles in thyroid, lung, and developing brain morphogenesis. Because TTF1-expressing neoplasms are generated from organs and tissues that normally express TTF1, such as the thyroid follicular epithelium and peripheral lung airway epithelium, TTF1 is widely used as a cell lineage-specific and diagnostic marker for thyroid carcinomas and for lung adenocarcinomas with terminal respiratory unit (TRU) differentiation. However, among lung neuroendocrine tumors, small-cell carcinomas (small-cell lung cancers (SCLCs)), most of which are generated from the central airway, also frequently express TTF1 at high levels. To clarify how SCLCs express TTF1, we investigated the molecular mechanisms of its expression using cultivated lung cancer cells and focusing upon neural cell-specific transcription factors. Both SCLC cells and lung adenocarcinoma cells predominantly expressed isoform 2 of TTF1, and TTF1 promoter assays in SCLC cells revealed that the crucial region for activation of the promoter, which is adjacent to the transcription start site of TTF1 isoform 2, has potent FOX-, LHX-, and BRN2-binding sites. Transfection experiments using expression vectors for FOXA1, FOXA2, LHX2, LHX6, and BRN2 showed that BRN2 substantially upregulated TTF1 expression, whereas FOXA1/2 weakly upregulated TTF1 expression. BRN2 and FOXA1/2 binding to the TTF1 promoter was confirmed through chromatin immunoprecipitation experiments, and TTF1 expression in SCLC cells was considerably downregulated after BRN2 knockdown. Furthermore, the TTF1 promoter in SCLC cells was scarcely methylated, and immunohistochemical examinations using a series of primary lung tumors indicated that TTF1 and BRN2 were coexpressed only in SCLC cells. These findings suggest that TTF1 expression in SCLC is a cell lineage-specific phenomenon that involves the developing neural cell-specific homeoprotein BRN2.

A possible mechanism for 2,3',4,4',5'-pentachlorobiphenyl-mediated decrease in serum thyroxine level in mice.

The effect of 2,3',4,4',5'-pentachlorobiphenyl (CB118) on serum total thyroxine (T4) level was comparatively examined between C57BL/6 and DBA/2 mice, which are sensitive and insensitive, respectively, to aryl hydrocarbon receptor-mediated biological changes. After 5 d of CB118 administration (50 mg/kg, intraperitoneally (i.p.)), the serum total T4 levels in both strains of mice were markedly decreased. However, significant decreases in serum thyroid-stimulating hormone levels were observed in DBA/2 mice, but not in C57BL/6 mice. In contrast, significant increases in the level and activity of hepatic T4-uridine 5'-diphosphate (UDP)-glucuronosyltransferase by CB118 treatment were observed only in C57BL/6 mice. Likewise, significant increases in the amounts of biliary [(125)I]T4 and [(125)I]T4-glucuronide after injection of [(125)I]T4 were observed only in the CB118-pretreated C57BL/6 mice. The CB118-mediated changes in the levels of [(125)I]T4 bound to transthyretin (TTR), albumin, and thyroxine binding globulin (TBG) were also observed in C57BL/6 mice, but not in DBA/2 mice. Despite such strain differences, significant increases in the liver-selective accumulation of [(125)I]T4 by CB118-pretreatment was observed in both C57BL/6 and DBA/2 mice. The present findings indicate that CB118-mediated decreases in levels of serum T4 in C57BL/6 and DBA/2 mice occur mainly through enhanced accumulation of hepatic T4.

POU domain transcription factor BRN2 is crucial for expression of ASCL1, ND1 and neuroendocrine marker molecules and cell growth in small cell lung cancer.

BRN2 is a developmental neural cell-specific POU domain transcription factor and is crucial for cell lineage determination. We investigated the importance of BRN2 in the expression of the lineage-specific transcription factors (achaete-scute homolog-like 1 (ASCL1) and NeuroD1 (ND1)) and neural/neuroendocrine marker molecules (neural cell adhesion molecule 1 (NCAM1), synaptophysin (SYP) and chromogranin A (CHGA)) in small cell lung cancer (SCLC) using cultured lung cancer cells. All examined SCLC cell lines expressed BRN2, as well as ASCL1, ND1, NCAM1, SYP and CHGA. The expression levels of ASCL1, ND1, NCAM1, SYP and CHGA considerably decreased when BRN2 was knocked down in SCLC cells, and the addition of a BRN2 transgene into non-SCLC (NSCLC) cells induced the expression of ASCL1, ND1, NCAM1, SYP and CHGA. However, the BRN2 gene was not activated by the forced expression of ASCL1 or ND1 in NSCLC cells. The knockdown of BRN2 caused significant growth retardation with decrease of S to G2 phase population and mitotic cell rates and unaltered Ki-67-labeled or apoptotic cell rates in SCLC cells, indicating increase of G1 phase population. These findings suggest that BRN2 is a higher level regulator than ASCL1 and ND1 and BRN2 might be involved in aggressiveness of SCLC.